Australia's Jason Day held the upper hand over Victor Dubuisson midway through the final of the £5.4million WGC-Accenture Match Play Championship on Sunday.
Day was conceded the first two holes of the final as Dubuisson got off to a shaky start before rallying to get back on level terms in the early stages at Dove Mountain.
However, the Frenchman then bogeyed the fifth, sixth and seventh and lost the last two of those holes, before also losing the ninth when his approach from an ideal spot on the fairway was pulled well left of the green.
The 23-year-old was entitled to a free drop as a spectator grandstand was blocking his route to the green, but his ball came to rest up against a rock and that prompted another concession and three-hole deficit.
Dubuisson had also been three down after four to the veteran Ernie Els in their semi-final, but the Turkish Airlines Open winner made a crucial par save from 15ft on the seventh to avoid going further behind and then birdied three of the next four holes to get back on level terms.
A par on the 12th was enough to give Dubuisson his first lead of the day as the match began to swing back and forth, Dubuisson making a mess of the 14th but holing from six feet for a birdie on the 15th to get back in front.
Els then holed from long range on the 16th to make it all square, but the 2012 Open champion then bogeyed the last after hitting his approach into a greenside bunker to send Dubuisson into the final.
That meant Dubuisson was guaranteed at least £545,000, which effectively secures his Ryder Cup debut at Gleneagles in September.
Dubuisson put his bad start down to being nervous of taking on his idol Els in his first WGC event, telling Sky Sports: "It feels great (to win), especially because this morning I was not feeling comfortable.
"I didn't sleep very well and when I arrived at the course I realised I was in the semi-final of a World Golf Championship event against Ernie Els. I am a big fan of him, always watching him winning majors, and I was not as comfortable as the round before. That's why I had a poor start.
"I made three or four very bad shots and then I tried to focus again on my game and knew I had to play my best golf. That's what I did and proved my mentality is very solid."
Day was certain of achieving a career-high world ranking after reaching the final by beating Rickie Fowler 3&2 in the last four. The World Cup winner will climb from 11th to fourth with a first WGC title, or to sixth by finishing runner-up.
The 26-year-old looked to be cruising to victory when he led by three holes with seven to play, but lost the next two to give Fowler hope of mounting a successful comeback.
However, Fowler then bogeyed the 15th after chipping across the green and into a drainage ditch and the match came to an anti-climactic end as the American three-putted the 16th from six feet.
"I knew Jason was going to be tough," Fowler told Sky Sports. "He made quite a few good putts, he didn't give me a whole lot. He missed a par putt on 12 but other than that he played solid all day.
"On 15 I was in a tough position, I couldn't really make anything of it and 16 was a complete mis-read. Jason played well and he's going to be tough to beat this afternoon."